International Journal of Rock Mechanics and Mining Sciences最新文献_第3页

Deterioration characteristics of red beds lithological interface under water-rock interaction and its influence on tunnel deformation 水岩作用下红层岩性界面劣化特征及其对隧道变形的影响

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-29 DOI: 10.1016/j.ijrmms.2026.106434

Jingkai Qu , Yiguo Xue , Fanmeng Kong , Cuiying Zhou , Jianbing Peng , Su Yan , Zhen Liu , Zhuang Ruan , Mingdong Zang , Kang Fu , Bo Wang , Minghao Jia , Ze Shi , Ziming Qu , Huaibing Wang , Xinyu Liu

Red beds exhibit pronounced hydro-sensitivity and softening characteristics, which commonly trigger significant tunnel deformation and instability hazards. Based on the Fengtun Tunnel deformation in China, this study employs an integrated methodology to reveal the deterioration characteristics of red beds lithological interfaces under water-rock interaction and their control on tunnel deformation. The results indicate that deformation is intense during the initial excavation stage, with maximum rates reaching 20 mm/d. More than 75 % of the cumulative deformation occurs prior to initial support of invert. Notably, the deformation exhibits extreme sensitivity at the mudstone-sandstone interface, characterized by drastic fluctuations in deformation rates. The fundamental cause of this behavior lies in the distinct deterioration modes of the two rock types under water-rock interaction. Following saturation, the mudstone uniaxial compressive strength and elastic modulus decrease by 37 % and 55 %, respectively, due to cement dissolution and mineral loss. Conversely, the sandstone exhibits only a minor strength reduction of 3 % and 15 %, respectively, though its porosity increases significantly. This differential degradation drives an evolution in the deformation mechanism, shifting from “stress driven” mode in the mudstone section to “hydro-mechanically driven” mode in the sandstone section. This transition generates a displacement differential of up to 30.0 mm between spandrel and arch waist on the same side. The consequent concentration of asymmetric shear stress on the support structure is identified as the root cause of localized shear failure. This research provides a scientific basis for disaster prevention and the design of resilient support systems in red beds tunnels.

红层具有明显的水敏性和软化特性，通常会引发严重的隧道变形和失稳危险。以中国丰屯隧道变形为研究对象，采用综合方法揭示了水岩作用下红层岩性界面的变质特征及其对隧道变形的控制作用。结果表明：开挖初期变形剧烈，最大变形速率可达20 mm/d；超过75%的累积变形发生在仰拱的初始支撑之前。值得注意的是，变形在泥岩-砂岩界面处表现出极端的敏感性，其特征是变形速率的剧烈波动。造成这种现象的根本原因在于两种岩石在水岩相互作用下的不同变质模式。饱和后，泥岩单轴抗压强度和弹性模量分别因水泥溶解和矿物损失下降37%和55%。相反，砂岩的强度下降幅度较小，分别为3%和15%，但孔隙度显著增加。这种差异退化推动了变形机制的演变，从泥岩段的“应力驱动”模式转变为砂岩段的“水机械驱动”模式。这种过渡在同一侧的拱腰和拱肩之间产生了高达30.0毫米的位移差。由此产生的不对称剪应力集中在支护结构上，被认为是局部剪切破坏的根本原因。该研究为红层隧道的灾害预防和弹性支护系统设计提供了科学依据。

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引用次数: 0

Time-Feature Fused Transformer model: A study on TBM performance prediction and attention evolution patterns 时间特征熔断变压器模型：TBM性能预测与注意力演化模式研究

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-28 DOI: 10.1016/j.ijrmms.2026.106427

Wenkun Yang , Zuyu Chen , Haitao Zhao , Jianchun Li , Shuo Chen , Chong Shi , Dong Chen , Jing Li

Accurate prediction of Tunnel Boring Machine (TBM) performance is critical for optimizing operational parameters and enhancing excavation efficiency. Existing intelligent methods for real-time performance assessment primarily treat this task as either a time-series forecasting or a multi-factor regression problem, failing to explain the evolutionary patterns of attention weights across temporal and feature dimensions. To address this gap, this study proposes a Time-Feature Fused Transformer (TFFT) model, which utilizes parallel-connected time-attention and feature-attention layers, followed by a regression layer. This architecture extracts multi-head self-attention weights from both dimensions, enabling analysis of attention evolution mechanisms during rock mass quality improvement or deterioration. Then, field-monitored data from the Songhua River water conveyance tunnel (YS), which is 19.77 km long, is used for model training, hyperparameter optimization, and testing. The TFFT demonstrates superior performance over five designed attention structures and state-of-the-art machine learning benchmarks through its ability to fuse temporal and feature representations effectively. Besides, attention weights analysis indicates temporal attention shifts toward earlier time steps during rock quality deterioration but concentrates on larger time steps during improvement, while feature attention remains invariant across the changed rock mass classes. Engineering applications on the new 8.6-km-long Chaoer to Xiliao tunnel (YC) confirm the model's robustness in providing real-time thrust predictions for operational guidance and exhibit a similar attention evolution mechanism to the YS tunnel. This work advances the fusion of temporal and feature learning in TBM performance prediction, offering more insights into spatio-temporal feature fusion and attention evolution patterns, as well as significant implications for safety and efficiency in tunnelling projects.

隧道掘进机性能的准确预测是优化施工参数、提高掘进效率的关键。现有的智能实时性能评估方法主要将此任务视为时间序列预测或多因素回归问题，无法解释注意力权重在时间和特征维度上的演化模式。为了解决这一差距，本研究提出了一种时间特征熔合变压器（TFFT）模型，该模型利用并联的时间注意层和特征注意层，然后是回归层。该体系结构从两个维度提取多头自注意权值，从而能够分析岩体质量改善或恶化过程中的注意演化机制。然后，利用19.77 km长的松花江输水隧洞现场监测数据进行模型训练、超参数优化和试验。TFFT通过有效融合时间表征和特征表征的能力，在五种设计的注意力结构和最先进的机器学习基准上表现出卓越的性能。此外，注意权值分析表明，在岩体质量恶化过程中，时间注意力向较早的时间步长转移，而在岩体质量改善过程中，时间注意力集中在较大的时间步长上，而特征注意力在不同的岩体类别中保持不变。在新建的长8.6公里的潮儿至西寮隧道（YC）上的工程应用证实了该模型在为操作指导提供实时推力预测方面的鲁棒性，并显示出与YS隧道相似的注意力演化机制。本研究推进了隧道掘进机性能预测中时间和特征学习的融合，提供了更多关于时空特征融合和注意力演化模式的见解，并对隧道工程的安全和效率具有重要意义。

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引用次数: 0

Effects of CO2-water-rock interactions on the fracture performance of transversely isotropic shale: Transition from strengthening to weakening co2 -水-岩相互作用对横向各向同性页岩裂缝性能的影响：从强化到弱化的过渡

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-27 DOI: 10.1016/j.ijrmms.2026.106435

Xuefeng Li , Fengshou Zhang , Tiankui Guo , Changtai Zhou

The influence of CO₂-water-rock interactions on the fracture mechanical performance of transversely isotropic shale is a critical factor affecting the long-term safety of CO₂ sequestration in depleted shale reservoirs. In this study, a series of CO₂-water-rock reaction experiments combined with semi-circular bend (SCB) tests were conducted to investigate the macro- and microscopic mechanisms underlying the impact of CO₂-water-rock interactions on shale fracture performance. Shale specimens were exposed to CO₂ and water at a constant temperature of 50 °C prior to fracture toughness testing, with exposure times of 0, 10, 20, and 30 d and pressures of 6, 11, and 16 MPa. Control groups subjected to water-bath treatment and pure CO₂ treatment were also established. The experimental results indicate that reaction pressure is the primary factor governing the onset of fracture toughness degradation induced by CO₂-water-rock interactions: higher pressures lead to a more pronounced weakening effect. The phase transition of CO₂ under different reaction pressures markedly alters the evolution pathway of shale fracture toughness and the influence exerted by CO₂-water-rock interactions on fracture toughness. The presence of water significantly enhances both the reactivity and pressure sensitivity of CO₂-rock reactions. As exposure time increases, the effect of CO₂-water-rock interactions on shale fracture toughness transitions from a strengthening to a weakening effect. In the short-term reaction, extensive contact between shale, CO₂, and water induces the formation of widely dispersed physical dissolution micropores, enhancing the fracture resistance of shale. In contrast, long-term reaction promotes sustained chemical dissolution of locally reactive minerals, producing enlarged dissolved pores and a pronounced deterioration in both material strength and fracture toughness. The evolution of clay mineral content plays a decisive role in the time-dependent behavior of shale fracture toughness. These findings enhance the understanding of the macro- and microscopic mechanisms governing CO₂-water-rock interactions in the context of CO₂ geological sequestration in depleted shale reservoirs, and provide essential theoretical support for evaluating storage potential and ensuring long-term reservoir integrity.

CO2-水-岩相互作用对横向各向同性页岩裂缝力学性能的影响是影响枯竭页岩储层CO2封存长期安全的关键因素。本研究通过一系列co2 -水-岩反应实验，结合半圆弯曲（SCB）试验，探讨co2 -水-岩相互作用对页岩压裂性能影响的宏观和微观机制。在进行断裂韧性测试之前，将页岩试样在50°C的恒温条件下暴露于CO2和水中，暴露时间分别为0、10、20和30 d，压力分别为6、11和16 MPa。同时建立水浴处理和纯CO2处理的对照组。实验结果表明，反应压力是co2 -水-岩相互作用导致断裂韧性退化发生的主要因素，压力越高，削弱作用越明显。不同反应压力下CO2的相变显著改变了页岩断裂韧性的演化路径以及CO2-水-岩相互作用对断裂韧性的影响。水的存在显著提高了co2 -岩石反应的反应活性和压力敏感性。随着暴露时间的延长，co2 -水-岩相互作用对页岩断裂韧性的影响由增强作用向减弱作用转变。在短期反应中，页岩、CO2和水之间广泛接触，形成广泛分散的物性溶解微孔，增强了页岩的抗裂性。相反，长期的反应促进了局部活性矿物的持续化学溶解，导致溶解孔隙扩大，材料强度和断裂韧性明显下降。黏土矿物含量的变化对页岩断裂韧性的时变行为起决定性作用。这些发现增强了对枯竭页岩储层二氧化碳地质封存背景下二氧化碳-水-岩相互作用的宏观和微观机制的理解，并为评估储层潜力和确保储层的长期完整性提供了重要的理论支持。

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引用次数: 0

Physics informed kriging convolutional graph attention network for predicting minimum horizontal stress from seismic attributes and finite element simulations 从地震属性和有限元模拟中预测最小水平应力的kriging卷积图注意网络

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-26 DOI: 10.1016/j.ijrmms.2026.106429

Muhammad Azam Khan , Yang Zhao , Mandella Ali M. Fargalla , Wyclif Kiyingi , Chenggang Xian , Chunduan Zhao , Liang Xing

Accurate mapping of minimum horizontal stress (Sh_min) is vital for wellbore stability, hydraulic fracturing design and reservoir management in heterogeneous formations. Traditional approaches rely on sparse one-dimensional measurements or on numerical simulations that provide high fidelity but are computationally expensive. We present a physics informed kriging convolutional graph attention network (PIKCN-GAT) that integrates seismic attributes with stress fields obtained from finite element method (FEM) simulations. The framework constructs a k nearest neighbor graph from four post stack seismic attributes (maximum curvature, minimum curvature, root mean square amplitude and variance) and uses multi head graph attention to aggregate information from neighboring nodes. A kriging branch captures local spatial correlation and a physics informed loss term based on Eaton's poroelastic relation enforces geomechanical plausibility. The method is demonstrated on a high-resolution dataset from the Longmaxi Formation in the Daan field, Sichuan Basin, China. We trained PIKCN-GAT on 146,145 grid nodes and evaluated it on an unseen set of 32,805 nodes. On the test set, it achieved R² of 0.93, RMSE of 0.81 MPa, and MAE of 0.64 MPa, outperforming baseline kriging convolutional networks without attention or physics constraints. Shapley additive explanations indicate that the minimum curvature and variance are the most influential attributes. The resulting two-dimensional stress maps identify zones of elevated stress and potential barriers to fracture propagation, providing valuable input for geomechanical modelling and field development planning.

准确绘制最小水平应力（Shmin）对于非均质地层的井筒稳定性、水力压裂设计和油藏管理至关重要。传统的方法依赖于稀疏的一维测量或提供高保真度但计算代价昂贵的数值模拟。我们提出了一个基于物理的克里格卷积图注意网络（PIKCN-GAT），该网络将地震属性与有限元模拟得到的应力场相结合。该框架从4个叠后地震属性（最大曲率、最小曲率、均方根振幅和方差）构建k个最近邻图，并利用多头图关注聚合相邻节点的信息。kriging分支捕获局部空间相关性，基于Eaton孔隙弹性关系的物理通知损失项增强地质力学合理性。在四川盆地大安油田龙马溪组高分辨率数据集上对该方法进行了验证。我们在146,145个网格节点上训练了PIKCN-GAT，并在一个未见过的32,805个节点上对其进行了评估。在测试集上，它的R2为0.93，RMSE为0.81 MPa， MAE为0.64 MPa，优于没有注意或物理约束的基线kriging卷积网络。Shapley加性解释表明，最小曲率和方差是影响最大的属性。由此产生的二维应力图确定了应力升高区域和裂缝扩展的潜在障碍，为地质力学建模和油田开发规划提供了有价值的输入。

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引用次数: 0

Experimental study on the permeability characteristics of reconsolidated salt: Effects of gas and confining pressure 重固结盐渗透率特性试验研究：气相和围压的影响

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-24 DOI: 10.1016/j.ijrmms.2026.106424

Zongze Li , Jinyang Fan , Yanfei Kang , Yang Zou , Marion Fourmeau , Jie Chen , Deyi Jiang , Daniel Nelias

Reconsolidated salt, formed from crushed halite under compaction, is a promising buffer and sealing material for deep geological repositories of high-level radioactive waste (HLW) because of its low permeability and self-healing properties. This study investigated the gas permeability behavior of reconsolidated salt with varying porosities under different confining pressures and inlet gas pressures using nitrogen gas. Based on nuclear magnetic resonance (NMR) technology, the pore structure of reconsolidated salt specimens with different porosities was tested and imaged. The experimental results demonstrate that gas permeability decreases with increasing gas and confining pressures, with gas pressure having a more pronounced effect. The observed permeability‒pressure relationship is attributed primarily to the Klinkenberg effect, with gas slippage along pore walls enhancing the measured permeability under low-pressure conditions. Using the Klinkenberg correction, the absolute permeability values of reconsolidated salt were derived, reaching as low as 10⁻¹⁹ m² in low-porosity samples. These values are significantly lower than the apparent gas permeability, indicating excellent sealing performance comparable to or superior to that of bentonite. A logarithmic relationship between the absolute permeability and confining pressure was established, providing a quantitative basis for permeability prediction under repository stress conditions. NMR imaging results indicate that with decreasing porosity, the connectivity between pores also gradually diminishes. Additionally, the slip factor was found to increase with increasing confining pressure, underscoring the evolving influence of pore geometry on gas transport mechanisms. Permeability of reconsolidated granular salt decreases with porosity following a power-law relationship, and the healing supports its sealing effectiveness. This study provides essential data and theoretical insights for evaluating the long-term sealing performance of reconsolidated salt in salt-based HLW repositories.

重固结盐是由岩盐压实形成的，由于其低渗透性和自愈性，是一种很有前途的高放射性废物深层地质处置库的缓冲和密封材料。利用氮气研究了不同围压和进口气体压力下不同孔隙度重固结盐的渗气行为。基于核磁共振（NMR）技术，对不同孔隙度重固结盐试样的孔隙结构进行了测试和成像。实验结果表明，渗透率随瓦斯压力和围压的增加而降低，其中瓦斯压力的影响更为明显。观察到的渗透率-压力关系主要归因于Klinkenberg效应，在低压条件下，气体沿孔壁滑动增强了测量的渗透率。利用Klinkenberg校正，导出了再固结盐的绝对渗透率值，在低孔隙度样品中渗透率可低至10 ~ 19 m2。这些值明显低于表观透气性，表明其密封性能与膨润土相当或优于膨润土。建立了绝对渗透率与围压之间的对数关系，为库区应力条件下渗透率预测提供了定量依据。核磁共振成像结果表明，随着孔隙度的减小，孔隙间的连通性也逐渐减弱。此外，滑移系数随着围压的增加而增加，这表明孔隙几何形状对气体输运机制的影响在不断变化。重固结颗粒盐的渗透率随孔隙度呈幂律关系降低，其愈合支撑了其密封效果。该研究为评价盐基高通量储存库中再固结盐的长期密封性能提供了必要的数据和理论见解。

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引用次数: 0

Microstructure-driven prediction of permeability and thermal conductivity in porous solids via a discrete multi-physics framework 基于离散多物理场框架的多孔固体渗透率和导热性的微观结构驱动预测

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-24 DOI: 10.1016/j.ijrmms.2026.106432

Changhao Liu , Andrey Jivkov , Kiprian Berbatov , Majid Sedighi , Jiangfeng Liu , Hongyang Ni

Accurate prediction of permeability and thermal conductivity of porous materials is essential for the design and optimisation of various engineering systems in energy, environmental and infrastructure applications. This study presents a discrete multi-physics modelling framework that enables direct prediction of these properties from microstructural information alone, without recourse to fitting against experimental data of fluid flow and heat transfer.

The method is based on combinatorial differential forms defined on a cell complex, allowing local conservation laws to be enforced while capturing material and interfacial non-linearities. Representative elementary volumes (REVs) were statistically reconstructed from high-resolution X-ray computed tomography (XCT) of two sandstone types, with mineralogical composition derived from X-ray diffraction (XRD) analysis. Local transport properties were assigned based on pore geometry and mineral-specific conductivities, incorporating realistic mixing rules at interfaces.

Simulations across 30 stochastic microstructural realisations per specimen of rock yielded permeability and thermal conductivity estimates that captured experimental trends and magnitudes without calibration. The results demonstrate the predictive capability and robustness of the approach, offering a viable pathway for microstructure-informed design and digital characterisation of porous and fractured geomaterials.

The central scientific contribution is a unified discrete operator formulation in which permeability and thermal conductivity emerge from the same mathematical structure, providing a physically consistent basis for modelling transport in heterogeneous and fractured rock materials.

准确预测多孔材料的渗透率和导热性对于能源、环境和基础设施应用中各种工程系统的设计和优化至关重要。本研究提出了一个离散的多物理场建模框架，可以仅从微观结构信息直接预测这些特性，而无需依赖于拟合流体流动和传热的实验数据。该方法基于在细胞复合体上定义的组合微分形式，允许在捕获材料和界面非线性的同时执行局部守恒定律。利用高分辨率x射线计算机断层扫描（XCT）对两种砂岩类型的代表性基本体积（REVs）进行了统计重建，并通过x射线衍射（XRD）分析得出了矿物成分。根据孔隙几何形状和矿物特有的导电性来分配局部输运性质，并结合界面上的实际混合规则。对每个岩石样本进行30种随机微观结构模拟，得出渗透率和导热系数估算，无需校准即可捕获实验趋势和量级。结果证明了该方法的预测能力和鲁棒性，为多孔和断裂岩土材料的微结构设计和数字化表征提供了可行的途径。其核心科学贡献是一个统一的离散算子公式，其中渗透率和导热系数来自相同的数学结构，为非均质和断裂岩石材料的运移建模提供了物理上一致的基础。

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引用次数: 0

An interpretable rock mass quality intelligent classification model (IRICM) driven by refined decision rule and its application 基于精细化决策规则驱动的可解释岩体质量智能分类模型及其应用

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-23 DOI: 10.1016/j.ijrmms.2026.106430

Xiang Wu , Fengyan Wang , Jianping Chen , Mingchang Wang , Lina Cheng , Chengyao Zhang , Junke Xu

Rock mass quality classification (RMQC) plays a crucial role in rock mass stability analysis and in the design and construction planning of rock engineering projects. However, current RMQC methods rely on expert experience, which makes it difficult for RMQC to be intelligent, scientific, and interpretable, and is not conducive to understanding rock mass characteristics in engineering applications. Therefore, this study proposes an interpretable rock mass quality intelligent classification model (IRICM) by coupling random forest (RF) and genetic algorithm (GA) to refine decision rules, aiming to enhance the intelligence, scientificity, and interpretability of RMQC. Based on 318 tunnel section data, the RMQC dataset was constructed using rock mass rating (RMR) parameters obtained from field investigations and laboratory experiments. By coupling RF and GA, the rules from all decision trees were selected, combined, and optimized to refine decision rules, achieving a classification accuracy of 87.50 % with only five rules per class. Interpretability analysis of the refined decision rules revealed that rock quality designation (RQD), intact rock strength (IRS), joint spacing (JS), and groundwater (GW) were the most frequently used features, confirming their importance in RMQC. Further analysis using post-hoc interpretability techniques also indicated that RQD, IRS, JS, and GW contributed most significantly to RMQC, especially in distinguishing poor rock mass quality (classes IV and V). The model was applied to the RMQC of tunnels and rock slopes, and the results demonstrated consistency with classification outcomes from the Q, RMR, and geological strength index (GSI) systems, validating its reliability and stability.

岩体质量分级在岩体稳定性分析和岩体工程设计与施工规划中起着至关重要的作用。然而，目前的RMQC方法依赖于专家经验，难以实现RMQC的智能化、科学性和可解释性，不利于工程应用中对岩体特征的理解。为此，本研究提出了一种可解释岩体质量智能分类模型（IRICM），通过随机森林（RF）和遗传算法（GA）的耦合来细化决策规则，以提高RMQC的智能性、科学性和可解释性。基于318条隧道断面数据，利用现场调查和室内试验获得的岩体质量等级（RMR）参数，构建RMQC数据集。通过耦合RF和GA，对所有决策树中的规则进行选择、组合和优化，以细化决策规则，实现了每类只有5条规则的分类准确率达到87.50%。精化决策规则的可解释性分析表明，岩石质量标识（RQD）、岩石完整强度（IRS）、节理间距（JS）和地下水（GW）是最常用的特征，证实了它们在RMQC中的重要性。使用事后可解释性技术的进一步分析还表明，RQD、IRS、JS和GW对RMQC的贡献最为显著，特别是在区分差岩体质量（IV类和V类）方面。将该模型应用于隧道和岩质边坡的RMQC，结果与Q、RMR和地质强度指数（GSI）系统的分类结果一致，验证了该模型的可靠性和稳定性。

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引用次数: 0

The Cosserat continuum with the hyperbolic Mohr-Coulomb failure surface and its applications to strength problems 具有双曲莫尔-库仑破坏面的Cosserat连续体及其在强度问题中的应用

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-23 DOI: 10.1016/j.ijrmms.2026.106425

Le Zhang, Hong Zheng

In the field of continuum mechanics, the Cauchy continuum model has traditionally held a dominant position. In contrast, the Cosserat continuum model, which serves as a significant complement to the Cauchy model, has primarily been used to address strain softening or to simulate the growth of shear bands. In the limited applications of the Cosserat continuum to strength problems, the elasto-plastic model employed takes the Drucker-Prager criterion as the failure criterion, rather than the Mohr-Coulomb criterion that better captures the failure characteristics of geomaterials. This is largely due to the fact that a non-smooth Mohr-Coulomb yield surface poses substantial challenges for elasto-plastic constitutive integration. To address this issue, this study develops a projection-contraction algorithm based on Gauss-Seidel iteration to implement stress updates within the framework of the Cosserat model, using a hyperbolic Mohr-Coulomb (HMC) criterion as the yield criterion. The Gauss–Seidel Projection-Contraction (GSPC) algorithm eliminates the need to compute the Hessian matrix of the yield function and exhibits superior numerical performance compared to the widely-used return-mapping method. Meanwhile, a displacement control method (DCM) is designed to bring models to the limit equilibrium state. This proposed procedure exhibits superior numerical performance compared to load control method (LCM) based on Newton iteration. Analysis of typical case studies reveals that the proposed method is free from mesh dependency and possesses robust numerical characteristics. In particular, the Cosserat continuum naturally regularizes strain localization in elastic–perfectly plastic problems, and the internal characteristic length significantly influences the thickness of shear bands and the distribution of plastic zones.

在连续介质力学领域，柯西连续介质模型历来占据主导地位。相比之下，作为柯西模型的重要补充，Cosserat连续体模型主要用于处理应变软化或模拟剪切带的生长。在Cosserat连续体对强度问题的有限应用中，所采用的弹塑性模型采用Drucker-Prager准则作为破坏准则，而不是更好地捕捉岩土材料破坏特征的Mohr-Coulomb准则。这主要是由于一个非光滑的莫尔-库仑屈服面给弹塑性本构积分带来了巨大的挑战。为了解决这一问题，本研究开发了一种基于Gauss-Seidel迭代的投影-收缩算法，以双曲Mohr-Coulomb （HMC）准则作为屈服准则，在Cosserat模型框架内实现应力更新。Gauss-Seidel投影-收缩（GSPC）算法不需要计算屈服函数的Hessian矩阵，与广泛使用的返回映射方法相比，具有优越的数值性能。同时，设计了位移控制方法（DCM），使模型达到极限平衡状态。与基于牛顿迭代的负荷控制方法（LCM）相比，该方法具有更好的数值性能。典型实例分析表明，该方法不受网格依赖，具有鲁棒性。特别是在弹塑性问题中，Cosserat连续体自然地规范了应变局部化，内部特征长度显著影响剪切带的厚度和塑性区的分布。

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引用次数: 0

Rapidly improving the acid-fracture conductivity in deep and ultra-deep carbonate reservoirs through mineral alteration: a new method 通过矿物蚀变快速提高深层和超深层碳酸盐岩储层酸缝导流能力的新方法

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-21 DOI: 10.1016/j.ijrmms.2026.106415

Xiang Chen , Zhaoxu Deng , Pingli Liu , Tianyu Zhang , Juan Du , Hongming Tang , Haitai Hu , Xuan Gao , Zhongxuan Wang , Xiaotian He

Deep and ultra-deep carbonate reservoirs contain abundant geothermal and natural gas resources, and the conductivity of acid-fractured fractures is a critical factor determining the development efficiency of these resources. However, high closure stress and acid-induced damage can lead to fracture closure and conductivity degradation. Mineral alteration refers to the in-situ conversion of existing minerals into new compounds, but the mineral alteration process is currently too slow (72 h). The Na₂HPO₄ + H₃PO₄ buffer solution (PPN) has been preliminarily proven effective in rapidly enhancing rock strength. This study investigated the effects of different acid systems (gelling acid and organic acid) and PPN treatment at 200 °C on the etching morphology, hardness, and fracture conductivity of dense carbonate rocks from two formations: the Mao-kou limestone and the Jialingjiang argillaceous limestone. The experimental results confirm that PPN rapid treatment under ultra-high temperature is effective in enhancing the fracture conductivity under high closure stress, and also reveal its mechanism of action. After 4 h of PPN treatment at 200 °C, the fracture conductivity of the Mao-kou formation and Jialingjiang formation samples increased by factors of 29.4 and 19.0, respectively, compared with untreated samples. Acid dissolution caused the rock's microstructure to transform from being dense and compact to becoming loose, with numerous dissolution pores and micro-fractures. In contrast, PPN treatment converted carbonate minerals on the fracture surfaces in situ into harder hydroxyapatite and repaired acid-induced structural damage, thereby enhancing rock strength and deformation resistance, resulting in smaller fracture-closure displacement under stress. Acid-induced damage reduced the hardness of Mao-kou formation and Jialingjiang formation samples by up to 25.6 % and 36.9 %, respectively. PPN treatment was effective for both limestone and argillaceous limestone, with the maximum increases in rock hardness reaching 39.4 % and 29.8 %, respectively. The organic acid produced a more heterogeneous etching morphology in the argillaceous limestone than the gelling acid did in the limestone. This study provides a new pathway for the rapid construction of high-conductivity fractures in deep and ultra-deep reservoir and efficient energy development.

深层和超深层碳酸盐岩储层蕴藏着丰富的地热和天然气资源，酸压裂缝的导流能力是决定这些资源开发效率的关键因素。然而，高闭合应力和酸致损伤会导致裂缝闭合和导流能力下降。矿物蚀变是指现有矿物在原位转化为新的化合物，但目前矿物蚀变过程太慢（72小时）。初步证明Na2HPO4 + H3PO4缓冲溶液（PPN）具有快速提高岩石强度的效果。研究了不同酸体系（胶凝酸和有机酸）和200℃PPN处理对茂口灰岩和嘉陵江泥质灰岩两组致密碳酸盐岩刻蚀形貌、硬度和裂缝导电性的影响。实验结果证实了超高温下PPN快速处理能有效提高高闭合应力下的裂缝导流能力，并揭示了其作用机理。经200℃PPN处理4 h后，茅口组和嘉陵江组样品的裂缝导电性分别比未处理样品提高29.4倍和19.0倍。酸溶蚀使岩石微观结构由致密致密向疏松转变，溶蚀孔和微裂缝大量存在。相比之下，PPN处理将裂缝表面的碳酸盐矿物原位转化为更硬的羟基磷灰石，修复了酸引起的结构损伤，从而提高了岩石的强度和抗变形能力，从而减小了应力作用下的缝闭位移。酸损害使茅口地层和嘉陵江地层样品的硬度分别降低25.6%和36.9%。PPN处理对灰岩和泥质灰岩均有效，岩石硬度最大增幅分别达到39.4%和29.8%。有机酸在泥质石灰岩中产生的蚀刻形态比胶凝酸在石灰岩中产生的蚀刻形态更不均匀。该研究为深层和超深层储层高导流裂缝的快速建设和高效能源开发提供了新的途径。

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引用次数: 0

Rockburst in circular openings under varying confining stress: Acoustic emission characteristics and precursors 不同围应力下圆孔岩爆：声发射特征和前兆

IF 7.5 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

International Journal of Rock Mechanics and Mining Sciences

Pub Date : 2026-01-20 DOI: 10.1016/j.ijrmms.2026.106418

Yang Wang , Murat Karakus , Dongqiao Liu , Manchao He , Yunpeng Guo

Rockburst induced by high in-situ stress is a major threat to the stability of underground structures. Among various controlling factors, confining stress plays a decisive role in governing the initiation, development, and intensity of rockburst. In this study, true triaxial rockburst experiments were conducted on sandstone specimens containing a circular hole under five levels of confining stress. The failure process was monitored through real-time video and acoustic emission (AE) techniques. AE energy, entropy, and microcrack mechanisms were analyzed to characterize the evolution of failure. Two precursor indicators, namely variance based on Critical Slowing Down (CSD) theory and the Hurst exponent derived from Rescaled Range (R/S) analysis, were employed to identify early warning signals. Results show that higher confining stress leads to greater energy accumulation, stronger tangential stress concentration, more abrupt failure behavior, and increased damage brittleness. The variance parameter was more sensitive to sudden failure, whereas the Hurst exponent provided earlier indications of instability. A two-stage damage fitting model revealed accelerated damage growth and increased brittleness with rising confining stress. These findings improve the understanding of rockburst evolution under different stress conditions and contribute to the development of more reliable early warning systems for deep underground engineering.

高地应力诱发的岩爆是威胁地下结构稳定的主要因素。在各种控制因素中，围应力对岩爆的发生、发展和强度起决定性作用。本研究对含圆孔砂岩试样在5级围应力条件下进行了真三轴岩爆试验。通过实时视频和声发射（AE）技术监测破坏过程。分析了声发射能量、熵和微裂纹机制，表征了破坏的演化过程。采用两个前兆指标，即基于临界慢化（CSD）理论的方差和基于重尺度极差（R/S）分析的Hurst指数来识别预警信号。结果表明：围应力越高，能量积累越大，切向应力集中越强，破坏行为越突然，损伤脆性越高；方差参数对突然失效更敏感，而赫斯特指数提供了不稳定的早期迹象。两阶段损伤拟合模型表明，随着围应力的增加，损伤扩展加速，脆性增加。这些发现提高了对不同应力条件下岩爆演化的认识，有助于开发更可靠的深部地下工程预警系统。

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引用次数: 0